internal static DatabaseField GetForeignKeyField(TableMetadata parentEntity, TableMetadata childEntity) { TableRelation[] relations = parentEntity.Relations; foreach (TableRelation relation in relations) { if (relation is ManyToManyTableRelation) { continue; } if (relation.RelatedTableName == childEntity.TableName) { return(childEntity.GetField(((ParentTableRelation)relation).ForeignKeyName)); } } throw new ArgumentException("No relation found between the specified tables"); }
/// <summary> /// Gets the data from a related table in a ManyToMany relation. /// </summary> /// <param name="relatedTableType">Type of the related entity</param> /// <param name="intermediaryRelatedTableType">Type of the intermediary table</param> /// <returns>TableMetadata array which contains the results</returns> protected Array GetRelatedTableData(Type relatedTableType, Type intermediaryRelatedTableType) { PersistentObject persistent = null; ManyToManyTableRelation relation = null; DataSet ds = null; try { //create a instance of the table so we can check the relations between out table and this TableMetadata relatedTable = (TableMetadata)Activator.CreateInstance(relatedTableType); TableMetadata intermediateTable = (TableMetadata)Activator.CreateInstance(intermediaryRelatedTableType); object primaryKeyValue = GetPrimaryKeyField().fieldValue; //first check the fieldValue of the primary key if (GetPrimaryKeyField().fieldValue == null) { throw new InvalidOperationException("The primary key does not have a fieldValue"); } //get the relation foreach (TableRelation var in Relations) { if (var is ManyToManyTableRelation) { if (var.RelatedTableName == relatedTable.TableName) { relation = (ManyToManyTableRelation)var; break; } } } //check if we got the relation if (relation == null) { throw new ArgumentException("A relation cannot be found between the tables"); } //we have the relation between the 2 tables. persistent = new PersistentObject(this); QueryCriteria qcThis = new QueryCriteria(TableName, GetPrimaryKeyField()); qcThis.Add(CriteriaOperator.Equality, GetPrimaryKeyField(), primaryKeyValue); //generate here the inner join QueryCriteria qcIntermediaryTable = new QueryCriteria(intermediateTable.TableName, intermediateTable.GetField(relation.IntermediaryKeyFieldFromParentTable)); QueryCriteria qcChild = new QueryCriteria(relatedTable); qcThis.AddJoin(JoinType.Inner, TableName, GetPrimaryKeyField(), intermediateTable.TableName, intermediateTable.GetField(relation.IntermediaryKeyFieldFromParentTable), qcIntermediaryTable); qcThis.AddJoin(JoinType.Inner, intermediateTable.TableName, intermediateTable.GetField(relation.IntermediaryKeyFieldFromChildTable), relatedTable.TableName, relatedTable.GetField(relation.IntermediaryKeyFieldFromChildTable), qcChild); ds = persistent.GetDataSet(qcThis); Array data = Array.CreateInstance(relatedTableType, ds.Tables[0].Rows.Count); for (int i = 0; i < data.Length; i++) { object instance = Activator.CreateInstance(relatedTableType); data.SetValue(instance, i); //loop thru dataset for (int j = START_INDEX_FIELD; j < ds.Tables[0].Columns.Count; j++) { Type tp = data.GetValue(i).GetType(); object[] args = new[] { ds.Tables[0].Columns[j].ColumnName, ds.Tables[0].Rows[i][j] }; tp.InvokeMember("SetFieldValue", BindingFlags.InvokeMethod | BindingFlags.Public | BindingFlags.Instance, null, instance, args); } } return(data); } catch { throw; } finally { if (ds != null) { ds.Dispose(); } } }